Inner tube



c. 7, 1924- y l,510,747

H. c. PRIVETT INNER TUBE v Filed March l, 1922 *lin Mala/ll@ f Patented @et 7, i924.

UNETE@ STES i taart rai-snr eric RY C. PRIVETT, 0F LOSANGELES, CALIFORNIA, ASSIGNOR 0F ONE-HALF T0 CHARLES ROBERT PRIVETT AND ONE-FOURTH T0 HOLLS F. PRIVETT, BOTH OF Lone BEACH, CALIFORNIA.

INNER, TUBE.

Application med March 1, 1922. serial n. 540,163.

To all whom t may concern:

Be it known that HENRY C. Pnlvn'rfr, a citizen of the United States residing at Los Angeles, in the county of State of California, haveinvented new and useful improvements in Inner Tubes, ofwhich the followin is a specification.

My invention re ates to inner tubes for pneumatic tires, and particularly to that type olf inner tube in which a reinforcing strip is embedded in the thickened tread portion for reventing. undue transverse expension of t e outer tread surface so as to effect a compression of the inner tread surface suiiicientI to provide self-sealing means for punctures.

ln tubes of the above type, the reinforcing strip is formed of a fibre, generally canvas, which is capable of longitudinal stretching only, the result being'that `in practice the stresses exerted transversely of the tube when the latter is inflated act to tear away the tube from the longitudinal edges of the reinforcing strip, thus preventing the strip from performing the function for which it is intended.

lt is the purpose of my invention to provide a reinforcing strip which is so'forrned that when incorporated in the tread portion of a tube it becomes an integral part, and while successfully retaining the outer surface from undue expansion, it eliminates all possibility of its edges becoming disengaged or tearing away from the rubber.

ln carrying out my invention l form the reinforcing strip of rubber in which is: embedded textile fibres such ascotton fibres. rilhe fibres are disposed transversely of the strip and substantially in two lengths, with the longer fibres disposed between the marginal edges of the strip and the short'fibres at the marginal edges. This arrangement of fibres allows of the necessary `longitudinal stretching of the strip to permit of its conforming to theV contour of the tube, but prevents transverse stretching of the strip in the area covered 'by such fibres. These long fibres terminate at the marginal edges ofthe strip and in so doingpermit of a transverse stretching of the marginal edges which, in conjunction `with the longitudinal stretching permitted as av result of the transverse arrangement of the short bres, positively los Angeles and i yprevents the disengagement vor tearing away a reinforcingl strip constructed in accordance with my invention.

2 is a sectional view of an inner tube having incorporated therein the reinforcing strip shown in Fig. l, the tube b/eing shown in the form it assumes prior to its reversal or to the position shown in Fig. 3.

Fig. 3 is a fragmentary perspective sectional view of the tube shown in Fig. 2 and 1n the position in which it is applied to a tlre casing.

Fig. 4 is a sectional view of a tire casing with the tube shown in Fig. 3 ininflated position therein.

Referring specifically to the drawings and particularly to Fig. 1, the reinforcing strip is designated at S and is shown as comprised of cotton waste and rubber of the samechar-` acter as that of which the tube isiformed. n forming the reinforcing strip, a relatively large sheet composed of cotton waste and rubber is rst formed by passing the waste and rubber through rollers (not shown) which serve to draw the cotton fibres in the same general direction within the sheet. This sheet of material is cuttransversely of its length into strips of suitable width so that the fibres contained within each strip are disposed transversely of its length. By forming the strips in this manner relatively long lengths of fibres are disposed along the longitudinal axis of each strip, while at the marginal edges of the strip are `located relatively short fibres. As previously explained. the long fibres serve to prevent transverse stretching of the strip, whilej the short fibres allow of a transverse stretching of the marginal edges of the strip. The arrangement of the long and short fibres within the strip is clearly illustrated in Fig. 1.

`When forming the inner tube shown in Fig. 2, the thickened tread portion 15 there of is vulcanized with the reinforcing strip proper position Within the tread portion and thus insuresk of the fibres performing the functions for which they are designed. As a result of the arrangement of the libres, the reinforcing strip is now free to stretch longitudinally, but transversely along its marinal edges only, so that when the tube is inflated and thus subjected to transverse stresses, the reinforcing strip Will give at its edges under the expanding action of the tube to'prevent disengagement or tearing away of the edges of: the strip from the rub! ber of the tube. lt is to be understood, hovw ever, that the long bres continue to prevent any appreciable stretching of the major portion of the strip so that the latter continues to prevent stretching of the outer tread surface of the tube when in applied position Within a tire casing as shown in llig. l.

W hat l claim is:

l. ln combination, an inner tube having a thickened tread portion, and a reinforcing Lawyer sheet embedded Within the tread portion and comprising a brous material completely impregnated with rubber and with the latter vulcanized with therubber of the tread portion for the purpose described.

2. A reinforcing strip for the tread portion of inner tubes comprising an elastic material, short and long inelastic members embedded Within the material and arranged transversely of the strip, the long members being arranged between the marginal edges of the strip, andthe short members at the marginal edges.

3. An inner tube forv an automobile tire mener e. reiterar. 

